Footwear with an adjustable stabilizing system, in particular for pronation and/or supination control

ABSTRACT

A footwear has a sole that comprises an adjustable stabilising system, in particular to control phenomena of pronation and/or supination. The stabilisation system comprises at least one adjustment member capable of selectively taking at least two alternative positions within a respective seat present in a component of the sole, the adjustment member having a body with at least two portions or sectors that present different degrees of compressibility.

BACKGROUND OF THE INVENTION

The present invention relates to footwear, particularly sports footwear,having a sole fitted with an adjustable stabilising system.

It is known that the gait, that is the placing of the foot on the groundduring walking or running, varies from person to person depending on themorphological and/or biomechanical characteristics of the subject. Somepeople rest their foot on the ground in a “neutral” manner, that issubstantially correctly from the biomechanical standpoint; on thecontrary in others some defect occurs in resting the foot on the ground,in particular due to excessive pronation (or inverted foot rest) orexcessive supination (or everted foot rest). Very briefly, in pronationthe foot takes on a position in which most of the body weight is loadedonto the inner (in technical jargon the medial) edge of the foot. On thecontrary, in supination the foot takes on a position in which the bodyweight is loaded onto the outer (in technical jargon the lateral) edgeof the foot. Even some people who are immune to gait defects whenwalking normally may suffer from excessive pronation or supinationduring running or sports activities in general.

For the above reasons, “neutral” footwear and “stable” footwear arecurrently available on the market, in particular for practising running.

The “neutral” footwear is provided with a midsole of uniform hardness orrigidity and is thus indicated for persons who do not suffer from anydefect in resting the foot. The “stable” footwear is, on the contrary,provided with a midsole of locally differentiated hardness or rigidityand is therefore indicated for persons who have problems of excessivepronation or supination, particularly noticeable during prolongedrunning.

Usually the midsoles of “stable” footwear have, in the medial zone ofthe heel, one or more insertions of greater hardness than the rest ofthe midsole and/or conformed so as to increase the resistance tocompression of the midsole in that area; in this manner greater supportmay be provided to the foot, controlling and/or supporting pronationwhen resting the foot on the ground. An example of this type of solutionis described in EP-A-0 315 340, and reference may also be made to theintroduction of this prior document for a detailed examination of theproblem mentioned above.

Manufacturers of footwear must therefore produce both “neutral” footwearand “stable” footwear and, in the case of “stable” footwear fitted withinserts, it is also necessary that manufacturers produce numerousversions of a single model of footwear, differentiated one from anotherin terms of the hardness or compressibility of the relative midsole (ashas been seen, the load when resting the foot on the ground variesdepending on biomechanics and the person's weight).

This diversification of production involves problems both for thefootwear manufacturer, who must set up diversified plant, and for theretailer, who must acquire a larger number of versions of a single modelof footwear in the attempt to meet consumers' differing demands.

In view of resolving these drawbacks, footwear has been proposed inwhich the midsole is fitted with inserts defining at least one airchamber, fitted with valve-operated means of control and capable ofbeing inflated to different pressures; in solutions of this type theoperative configuration of the midsole may therefore be modifieddepending on the extent of pronation that must be corrected. An exampleof this technique is described in WO 98/56272. Solutions of the typeindicated are complicated and expensive, as well as difficult to use forthe purpose of adjusting the degree of compressibility of the midsole;apart from this, should said valve break the adjustment system wouldbecome unusable.

From the document EP-A-0 258 718 footwear for practising running is alsoknown in which the means that oppose excessive pronation comprises acushioning strip, which embraces the midsole externally at the heelzone; the strip is fixed in a removable manner to the midsole, so as toenable it to be replaced if necessary. This solution has been found tobe unreliable over time, chiefly because use of the footwear involves arisk of damaging the cushioning strip and the means that enable it to befixed in a removable fashion to the midsole.

SUMMARY OF THE INVENTION

In the light of the above, the present invention aims to producefootwear provided with a new system of adjustable stabilisation,particularly to control pronation and/or supination, of simple andeconomic construction, as well as being versatile and reliable in use.In this general sphere, a particular purpose of the invention is toproduce footwear having a stabilising system conceived to facilitate andsimplify the phase of adjusting the degree of compressibility of therespective sole, be this carried out by the producer, the retailer orthe consumer.

This and further purposes, which will become clearer below, are achievedaccording to the present invention by footwear having thecharacteristics indicated in the attached claims, which constitute anintegral part of the descriptive content of this patent application.

BRIEF DESCRIPTION OF THE DRAWINGS

Further purposes, as well as the characteristics and advantages of thepresent invention, will be clear in the description that follows and inthe attached drawings, provided as a simple example for explanatorypurposes with no limiting intent, in which:

FIG. 1 is a view in elevation and partial section in diagram form ofsports footwear according to the invention;

FIGS. 2 and 3 are views in lateral elevation in diagram form of the sidedefined as “lateral” and of the side defined as “medial” of a midsole ofthe footwear in FIG. 1;

FIGS. 4 and 5 are views in diagram form, respectively in plan and inlateral elevation, of a main body of the midsole in FIGS. 2 and 3;

FIGS. 6 is a diagrammatic section along the line VI-VI of FIG. 4;

FIG. 7 is a front elevation in diagram form of an adjustment memberbeing part of a stabilising system of the footwear according to theinvention;

FIG. 8 is a diagrammatic section along the line VIII-VIII of FIG. 7;

FIGS. 9 and 10 show, in diagram form, respectively in front and lateralelevation, an insert of the member in FIGS. 7 and 8;

FIG. 11 is a section in diagram form along the line XI-XI of FIG. 10;

FIG. 12 is a diagrammatic plan of the midsole in FIGS. 2 and 3,including the body in FIGS. 4-6, the member in FIGS. 7-8 and the insertin FIGS. 9-11;

FIG. 13 is a diagrammatic section along the line XIII-XIII of FIG. 12;

FIG. 14 is a front elevation in diagram form of an adjustment memberbeing part of a stabilising system according to a possible variant ofthe invention;

FIG. 15 is a section in diagram form along the line XV-XV in FIG. 14.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1, footwear for athletics or for practising running, fabricatedaccording to the invention, is indicated overall as 1; the footwear 1has an upper part or upper 2 and a lower part or sole that, in the casegiven as an example, comprises an outsole 3 and a midsole 4.

The specifics of the upper 2 and of the outsole 3 lie outside the scopeof the present invention and will therefore not be illustrated ordescribed in detail; it suffices here to mention that the outsole 3 maybe made of synthetic material, for example rubber of differentiatedhardness, formed in a single piece or in a number of separate pieces.

The midsole 4 has a body 4 a that presents an upper face, a lower faceand a peripheral profile or edge; this peripheral profile has a lateralsegment, shown in FIG. 2, and a medial segment, shown in FIG. 3; themedial segment is substantially the part of the peripheral profile ofthe midsole 4 that faces towards the other foot of the user when thefootwear 1 is being worn, whereas the lateral segment is substantiallythe part of the peripheral profile opposed to the medial segment.

The midsole 4 is positioned between the upper 2 and the outsole 3 and onit, inside the footwear 1, rests an arch-support insole, not shown; forthis purpose a hollow 4 b is defined in the upper zone of the midsole 4,within which said insole is at least partially housed.

The body 4 a of the midsole 4 may be obtained by moulding a compressiblematerial that is elastic and light, such as for example EVA, and thenjoined to the upper 2, for example by gluing it around the peripheralzone of its upper face; the outsole 3 may be associated to the lowerface of the body 4 a by gluing.

According to the main aspect of the invention, the midsole 4 is fittedwith an adjustable stabilising system, to control pronation and/orsupination, indicated (as a whole) with D in FIG. 1.

FIGS. 4-6 show the body 4 a of the midsole 4; in these figures only thelateral segment of the body 4 a is illustrated (FIG. 5), but it shouldbe considered that fabrication is similar for the medial segment (seefor example FIG. 3).

As may be seen in FIG. 4, a cavity or seat 10 is present in theposterior part of the body 4 a, and in particular in the heel zone,having a prevalently circular lobed section; in the case shown as anexample, the peripheral wall of the seat 10 is shaped to define fourlobes 10 a, 10 b, 10 c, 10 d; the lobes 10 a, 10 b face respectivelytowards the anterior end and towards the posterior end of the body 4 a,whereas the lobes 10 c, 10 d face respectively towards the said medialsegment and the said lateral segment, and communicate through openpassages with the outside of the body 4 a. In correspondence with theseopen passages, covering elements 11 are mounted, shown in particular inFIGS. 5 and 6; in the example the elements 11 are formed at least inpart of transparent synthetic material, so as to form windows 11 a thatface onto the inside of the seat 10, as is visible for example in FIG.5. As will be clear below, the windows 11 embody means of inspection,for the purpose of allowing the type of adjustment set on thestabilising system, that is the specific object of the invention, to bechecked visually.

The seat 10 is destined to receive an adjustment member, indicated with12 as a whole in FIGS. 7 and 8, whose shape is substantiallycomplementary to that of the seat 10, but of slightly smaller size. Themember 12 thus substantially has the shape of a disk defining, along itsperipheral wall, four lobes 12 a, 12 b, 12 c, 12 d, at approximately 90°one from another.

The member 12 is formed such as to present adjacent sectors or portionsof differing hardness, that is having different degrees ofcompressibility. In the case given as an example, and as is shown inFIG. 7, the member 12 comprises three sectors, indicated with S1, S2 andS3, where the sector S1 includes the lobes 12 a and 12 d, the sector S2includes the lobe 12 b and the sector S3 includes the lobe 12 c; as asimple example, the sector S1 may have a hardness of 55 Shore C, thesector S2 a hardness of 65 Shore C and the sector S3 a hardness of 75Shore C.

The member 12 may be formed of a single material, but with the varioussectors of differentiated hardness or density, or may be made ofdifferent materials of different hardnesses that form the respectivesectors. The material or materials constituting the member 12 might bepolymers, such as thermoplastic polyurethane (TPU), expandedtwo-component polyurethane (hexocyanate polyol) or Pebax™ (polyammideand TPU), or expanded cross-linking materials such as EVA, that can beinjected or heat formed. The synthetic body of the member 12 might alsobe configured so as to present a cavity of a substantially toroidalshape, subdivided into sub-chambers containing a fluid (such as air) atdifferent pressures, so as to define a corresponding number of sectorshaving different degrees of compressibility.

As FIG. 8 shows, a circular housing 12 e is formed in the lower face ofthe member 12, with at its centre a hexagonal seat 12 f; the member 12also presents a central axial hole 12 g, having an end that opens incorrespondence with the seat 12 f.

The housing 12 e is destined to receive an insert, here comprising aplate 13 shown in FIGS. 9-11, formed as a single piece of rigidmaterial, for example a thermoplastic material. The plate 13 presents acircular base wall 13 a, from the centre of which a tubular part oflimited height 13 b rises, which in the case given as an example has ahexagonal inner and outer section.

FIGS. 12 and 13 show the midsole 4 fitted with the adjustablestabilising system, respectively in plan and in section.

As may be seen, the member 12 is inserted within the seat 10, with thelobes 12 a-12 d of the member occupying the lobes 10 a-10 d of the seat.The lower face of the member 12, fitted with the plate 13, rests on thebottom of the seat 10. In the assembled condition, two opposing lobes ofthe member 12—in the example lobes 12 c and 12 d—are partially visiblethrough the windows 11 a of the covering elements 11.

Production of the midsole 4 is very simple.

The body 4 a of the midsole 4 may be moulded, for example in EVA, inways and employing means that are known, such as to present the seat 10with the relative passages for the elements 11; these elements 11, oftransparent material, may be over-moulded or co-moulded with the body 4,or applied subsequent to the formation of the body 4 a and glued to it.

The member 12, fitted with the plate 13, is then inserted into the seat10, with the tubular part 13 b of the plate 13 inserted into the seat 12f. The plate 13 is for preference glued inside the respective seat 12 eof the member 12, exploiting the wide flat surface of the base wall 13a.

After assembling the upper 2 onto the sole, an insole of the archsupport type may be assembled inside the footwear 1, in the hollow 4 b,thus covering the upper side of the adjustable stabilising system. Inthe condition shown, in correspondence with the windows 11 a of theelements 11 present on the medial and lateral segments of the peripheralprofile of the midsole 4, the lobes 12 c and 12 d of the member 12 arepartially visible. In the preferred embodiment of the invention, thevarious sectors S1, S2 and S3 have visibly differentiated colours orappearances, or bear different indications in the part visible throughthe windows 11 a.

The adjustable system of the footwear is very simple to operate.

The member 12, not being fixed in the seat 10 of the body 4 a, may berotated through 360° around an axis indicated as X in the figures, sothat selectively it may take up a plurality of possible positions withinthe seat 10. In the case shown as an example, four alternative angularpositions are provided for, defined by the number of lobes of the seat10 and of the member 12.

To produce rotation of the member 12 it is sufficient to insert the tipof an appropriate tool into the hole 12 g of the member 12; in the casegiven as an example this tool comprises an Allen key of suitable size toengage in the hexagonal section of the tubular portion 13 b of the plate13 (it is clear that the portion 13 b might be shaped so as toco-operate with the tip of a tool of a different type, such as ascrewdriver or a spanner with square section). Access to the hole 12 gmay be obtained by removing the arch-support insole from the footwear 1or, alternatively, a passage substantially coaxial with the hole 12 gmay be provided in the arch support insole.

Using the tool the member 12 may be made to rotate clockwise oranticlockwise in the seat 10, so as to position the sector S1-S3 ofinterest in the desired position of the medial or lateral part of theheel; as has been said, the member 12 is here predisposed to be rotatedby 90° to change position; in consequence there are four possibledifferent combinations of positions of the sectors is S1-S3 in themedial zone or lateral zone of the heel, and that is:

1) medial S3, lateral S1;

2) medial S2, lateral S1;

3) medial S1, lateral S3;

4) medial S1, lateral S2.

The stabilisation system described, with two or more differentiateddegrees of hardness, thus enables the degree of resistance tocompression of the midsole 4 to be varied for the purposes ofcontrolling pronation and/or supination of the foot.

In the adjustment phase, even when this is performed with thearch-support insole removed, the member 12 is for preference maintainedwithin the seat 10 by means of the extreme portions of its two opposedlobes inserted in the elements 11; as may be realised, rotationsubstantially comes about “stepwise” and is enabled thanks to thedeformability of the materials comprising the body 4 a and the member12; engagement between the lobes of the member 12 and those of the seat10 ensures that the adjusted position that is set will be maintained.

Thanks to the different colours or indications of the sectors S1, S2,S3, the adjustment that has been performed may be perceived directlyfrom outside the footwear 1 for the medial and lateral segments, throughthe windows 11 a of the elements 11.

From what is described above it is clear that the degree ofcompressibility of the midsole 4 may be modified in an extremely simplefashion, depending on the morphological and biomechanicalcharacteristics of the consumer. This is particularly advantageous, notonly for the manufacturers and retailers of the footwear, but also forthe consumer who may, at need, modify the adjustment in view ofdifferent occasions of use of the same footwear. The adjustablestabilisation system described may be inserted in any type of midsole offootwear for athletics or sports in general, for example for practisingrunning or tennis; the invention is capable of being used with any typeof footwear.

Naturally, the construction details and embodiments may be varied withregard to what is described and illustrated here, without therebydeparting from the scope of the present invention as defined by theattached claims.

In the example described above, without limiting intent, the systemaccording to the invention is operative in the heel zone of the footwear1, but it is clear that it could also be provided in the zone of theforefoot; one and the same footwear could if desired to be provided withmore than one adjustment systems D, for example one in the heel zone andthe other in the forefoot zone.

The number of positions of the member 12 that can be selected maynaturally be more or fewer than four, and may vary depending on the typeof footwear. The profile of the seat 10 and of the member 12 might alsobe different from that given as an example, the possibility remainingthat a plurality of selectable positions may be determined. Also thedimensions of the member 12 might be different depending on the type offootwear (in that light, for example, it is known that the midsoles oftraining footwear are in general wider and thicker than those ofcompetition footwear).

In a possible variant, for example for footwear to be used in thegymnasium, the system might be conceived so as to enable directadjustment from outside the footwear. In that variant, the elements 11are open, that is configured such as to comprise openings through whichrespective portions of the peripheral edge of the member 12 projectdirectly outside the midsole 4; in this fashion, the member 12 embodiesa sort of wheel, which may be made to rotate manually without the needfor tools, acting on said peripheral edge.

In another possible variant, the elements 11 and the relative passagesmay be omitted, and adjustment may be made by extracting andsubsequently re-inserting the member 12 into the seat 10, in a differentangular position than previously; in this case, the footwear 1 isprovided with a removable arch-support insole.

A possible variant of the invention is represented in FIGS. 14 and 15,which use the same reference numbers as the previous figures to indicatethe elements technically equivalent to those already described. In thisvariant the body of the member 12 is formed from a single material, forexample EVA, so as to define a plurality of chambers or containers ofair or other fluid, indicated with S1 a, S2 a and S3 a, at differentpressures; each chamber extends in a respective sector S1, S2, S3 of themember 12, in such a fashion that these sectors have differentiateddegrees of compressibility.

1. Footwear having a sole that comprises an adjustable stabilisingsystem, in particular to control phenomena of pronation and/orsupination, wherein the adjustment system comprises at least oneadjustment member capable of selectively taking at least two alternativepositions within a respective seat present in a component of the solethe adjustment member having a body with at least two portions orsectors that present different degrees of compressibility.
 2. Footwearaccording to claim 1, wherein different positions of said member withinsaid seat correspond to different positions of one said sector withrespect to a specific zone of the peripheral profile of the sole. 3.Footwear according to claim 2, wherein said seat extends between amedial zone and a lateral zone of the peripheral profile of the sole,and in at least one of said positions, a first of said sectors lies atleast partially in said medial zone and a second of said sectors (S1)lies at least partially in said lateral zone.
 4. Footwear according toclaim 1, wherein said member is angularly rotatable or can be moved in,or with respect to, said seat.
 5. Footwear according to claim 1, whereinsaid seat and said member have substantially complementary peripheralprofiles.
 6. Footwear according to claim 4, wherein said componentcomprises the body of a midsole of compressible material, said member isapproximately disk-shaped and said seat has an approximately circularsection.
 7. Footwear according to claim 4, wherein said seat and saidmember have peripheral profiles each defining two or more projections orlobes.
 8. Footwear according to claim 1, wherein said seat communicateswith at least one passage that opens onto a peripheral edge of saidcomponent of the sole, through said passage at least part of one of saidsectors being visible and/or accessible from outside the footwear. 9.Footwear according to claim 8, wherein said sectors have, at least inthe respective parts visible through said passage, different colours orappearances or indications one from another.
 10. Footwear according toclaim 8, wherein said passage is covered by an element formed at leastin part of transparent material.
 11. Footwear according to claim 4,wherein said member is arranged to be displaced angularly between saidalternative positions using a tool.
 12. Footwear according to claim 1,wherein each of said sectors presents at least one chamber containing afluid, the chambers of different sectors being at different pressures.13. Footwear according to claim 1, wherein said seat is formed in a heelpart of the sole.